The present invention relates to the field of communications, and, in particular, to a frame-based communications network utilized by consumers on customer premises.
As computers become more and more cost effective for the everyday consumer and for small businesses, such computers become more plentiful for use within local area environments such as homes, office buildings and the like. For example, within a home a person with a computer in the bedroom, and another in the living room, may want to share common files, utilize a common digital subscriber line (DSL), or otherwise transfer information between the computers. Accordingly, various technologies are being developed for computer interconnection of multiple computers located within such environments. One example of such technologies are the Home Phoneline Network Alliance (HPNA) specifications for local area network (LAN) computer interconnection which utilize existing telephone lines within the local environment for the transmission of data packets between the computers, as described in detail in copending U.S. patent application Ser. No. 09/826,239 filed on Apr. 4, 2001, entitled “Transceiver Method and Signal Therefor Embodied in a Carrier Wave for a Frame-Based Communications Network”, and as implemented in Broadcom Corporations' ILINE ™ family of products.
FIG. 1 shows in block diagram form a general home networking environment within which the present invention can be implemented. Home network 10 includes existing (installed) plain old telephone service (POTS) wiring 12, network clients 14, the computer port side of modem 16 and fax 18. POTS wiring 12 provides wiring infrastructure used to network multiple clients at a customer premises (e.g., home or office) 20. POTS wiring 12 can be conventional unshielded twisted pair (UTP) wiring that is generally routed internally in the walls of the customer premises 20 to various locations (e.g., rooms) within the customer premises. POTS telephones 26 are typically connected to POTS wiring 12. Subscriber loop 22(also called a local loop) is a physical wiring link that directly connects an individual customer premises 20 to the Central Office through telephone network interface 24, a demarcation point between the inside and outside of customer premises 20. Of particular importance for residential networks are systems that provide communication between computers as reliably and with as high a data rate as possible. Communication over residential telephone wiring is provided through frame-oriented link, media access and physical layer protocols.
Further, in most cases today, a home's entertainment center (e.g., televisions)is not networked in any way. Typically, a phone jack is not present at or near most home entertainment centers. It is normally too expensive or undesirable to add new wiring to provide a new phone jack. Likewise, an Ethernet LAN network connection is too costly and troublesome to provision for such home entertainment centers as opposed to its use in computer networking. Some cable television installers have used inexpensive HF band FM wireless modems to provide a simple, low bandwidth analog modem connection to the home entertainment system. This enables low-speed Internet access and pay-per-view services. These low speed wireless modem links are not suitable for high bandwidth, high quality video or Voice over IP (VoIP) services.
Other, higher bandwidth, wireless networking products such as those implementing the IEEE 802.11b specification and more recently the IEEE 802.1a specification are available, but these products suffer from poor link reliability over even fairly short transmission distances and cannot offer the low bit error rates necessary to carry digital video without significant interruption to the viewer. Additionally, high bandwidth wireless nodes are relatively expensive when compared to using HPNA 2.0 over existing coaxial cable. However, at or very near almost every home entertainment center there is pre-wired coaxial cable (e.g., RG-6 or RG-59 coax) that feeds the cable television or TV antenna signal to other rooms in the house. Typically, coax is installed to all the other likely entertainment locations in the house—the bedrooms, the study, the family room or lounge—making coax ideal for the delivery of high-speed digital content to exactly where it is desired.
In addition to physical installation considerations, when designing home networks another important consideration is spectral management. The coaxial cabling within a typical home is subject to several sources of ingress. In addition to the expected terrestrial broadcast and cable broadcast television signals, other intentional signals such as cable modems or set top box conditional access signals may be present. Examples of the several signals of services and frequencies that may be present on household coaxial cable and may interfere with each other are shown in FIG. 2. Additionally, there are some unintentional noise sources on the household coaxial cable. Older built-in TV tuners can generate significant amounts of intermediate frequency (IF) egress out of their antenna/cable TV F-connectors. Televisions that are directly connected to the coaxial cable may cause some interference to the HPNA signals on the coaxial cable.
Given the HPNA home networking system depicted in FIG. 1, and the desirability that the HPNA home networking system be interconnected to pre-existing coaxial cable system(s) within the home, such as one connecting cable TV, and the desirability of appropriately managing the spectrum on the coaxial cable network, a need therefore exists for a system, method and apparatus for transporting home networking frame-based communications signals over coaxial cables. The present invention provides a solution to meet such need.